Orthodontic elastic band

ABSTRACT

The orthodontic elastic band which is described is suitable for use with orthodontic arch brackets mounted on teeth misaligned from their desired positions. The band includes a plurality of spaced sections each provided with bracket engaging means in the form of bracket engaging apertures. Elastic connecting means in the form of elastic links are provided between adjacent sections for linking the latter. The elastic links are arranged for applying non-symmetrical (i.e., rotational) forces to said sections and the respective brackets when the elastic links are tensioned. The sections are substantially planar and tensioning of the elastic links results in a torqueing action about the respective brackets in the planes of the sections. When at least three sections are provided, the connecting links between successive adjacent sections may be arranged to exhibit different resistances to twisting. With the latter embodiment, rotation of a section outside of its plane produces torqueing action on opposing sides of the respective section about the arch wire.

United States Patent [1 1 Wallshein [4 1 *Jul 29,1975

[ ORTHODONTIC ELASTIC BAND Melvin Wallshein, 8645 Bay Pky., Brooklyn,NY. I 1214 [76] Inventor:

] Notice: The portion ofthe term of this patent subsequent to Apr. 16.1991. has been disclaimed.

[22] Filed: Apr. 22, 1974 211 Appl. No.: 462,658

Primary ExaminerRobert Peshock Attorney, Agent, or FirmFlynn & Frishauf[57] ABSTRACT The orthodontic elastic band which is described issuitable for use with orthodontic arch brackets mounted on teethmisaligned from their desired positions. The band includes a pluralityof spaced sections each provided with bracket engaging means in the formof bracket engaging apertures. Elastic connecting means in the form ofelastic links are provided between adjacent sections for linking thelatter. The elastic links are arranged for applying nonsymmetrical(i.e., rotational) forces to said sections and the respective bracketswhen the elastic links are tensioned. The sections are substantiallyplanar and tensioning of the elastic links results in a torqueing actionabout the respective brackets in the planes of the sections. When atleast three sections are provided, the connecting links betweensuccessive adjacent sections may be arranged to exhibit differentresistances to twisting. With the latter embodiment, rotation of asection outside of its plane produces torqueing action on opposing sidesof the respective section about the arch wire.

26 Claims, 8 Drawing Figures ORTHODONTIC ELASTIC BAND BACKGROUND OF THEINVENTION The present invention generally relates to orthodonticappliances, and more particularly to an orthodontic elastic bandsuitable for applying non-symmetrical forces to brackets to causetransverse, tilting, and uprighting movements of corresponding teeth.

Orthodontic devices and appliances are well known for use in movingteeth in various ways. One of the frequent orthodontic procedures is thedrawing of two adjacent teeth towards one another. Various spring andelastic devices have been proposed for moving teeth in this manner.However, many of the known orthodontic devices are unsatisfactorybecause they do not provide means for regulating the amount of tiltingwhich the tooth experiences while it is being moved transversely. Thisproblem arises due to the anchored nature of the tooth at its roots.Since the forces applied to a tooth can normally only be applied to theexposed portions thereof which extend beyond the gum, transverse forcesapplied to the teeth tend to cause tilting or uprighting movements dueto pivotting of the teeth about their rooted portions.

The problems generally encountered in moving teeth and orthodonticelastic bands are more specifically described in the originalapplication Ser. No. 310,572, issued as U.S. Pat. No. 3,803,715. Thatapplication teaches various types of elastic bands which can be utilizedto provide the desired movements or results. However, the bandsdescribed in the earlier case are generally continuous flat stripshaving substantially parallel opposing edges. The nature of the earlierdescribed elastic bands is such that they generate and apply symmetricalforces to the teeth with respect to the bracket or arch wire.Accordingly, while the previous elastic bands move the teeth in thedesired directions, they cannot compensate for undesired tilting action, above described, where this is desirable.

The present invention discloses an orthodontic elastic band whoseprimary function is to enhance the utility of the biassing devices ofthe type disclosed in the earlier application by permitting selectiveregulation of the tilting or uprighting forces which are applied to atooth while the same is being moved transversely. To this end, thepresent application discloses elastic strips which are provided withnotches and other discontinuities between respective bracket engagingapertures to provide non-symmetrical forces which are applied to thebrackets with respect to the arch wire. By appropriate selection of theconnecting links between bracket engaging sections, both the nature andmagnitude of the non-symmetrical forces applied to the brackets can beclosely regulated or controlled. Accordingly, while the elastic bandsdescribed in the present application can be utilized similarly as thosedescribed in the parent case, the non-symmetrical forces which areachievable with the present bands can be utilized with greatereffectiveness to counteract or enhance pivotting about the roots of thetooth as the latter is urged in a transverse direction. This permitstilting or uprighting or limiting excessive tilting and uprightingduring such orthodontic procedures.

There is also described in the parent application, an elastic band aportion of which is twisted about its length prior to mounting on abracket. Such twisting results in lingual or labial torqueing of atooth. However, the forces which generate the lingual or labialtorqueing upon a tooth correspondingly result in counter torqueingforces on the adjacent teeth on which the elastic band is mounted foranchoring purposes. The present invention also utilizes the concept ofapplication of non-symmetrical forces to relieve some of the excessivetorqueing counter-forces on anchoring teeth and redistributing theseforces over the entire arch, most of the forces being shifted in thedistal directions where the anchoring teeth are bigger and can withstandthe forces without being excessively shifted.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide an orthodontic elastic band which does not have the abovedescribed disadvantages.

It is another object of the present invention to provide an orthodonticband which is elastic and which is simple in construction and economicalto manufacture.

It is still another object of the present invention to provide anorthodontic elastic band which can selectively apply non-symmetrical(i.e.. rotational or tilting) forces to brackets of adjacent teeth.

It is yet another object of the present invention to provide anorthodontic band which can effectively and inexpensively regulatetilting or uprighting of a tooth while the latter is moved transversely.

It is a further object of the present invention to provide tilt limitingmeans associated with an orthodontic elastic band of the general typedescribed in the other objects which limits excessive tilting of thetooth as the band causes the teeth to move transversely andsimultaneously causes tilting or uprighting of the teeth.

It is still a further object of the present invention to provide anorthodontic elastic band which permits accurate regulation of transverseas well as torqueing forces on teeth within an orthodontic system.

It is yet a further object of the present invention to provide anorthodontic band which can apply lingual or labial torqueing forces toteeth and redistribute or shift the counter forces in the distaldirection of the arch to prevent excessive movement of adjacentanchoring teeth.

In order to achieve the above objects, as well as others which willbecome apparent hereafter, an orthodontic elastic band suitable for usewith orthodontic arch brackets mounted on teeth misaligned from theirdesired positions includes a plurality of spaced sections each providedwith bracket engaging means for engaging a respective bracket. Elasticconnecting means are provided between adjacent sections for linking thelatter. Said connecting means are arranged for applying rotationalforces to said sections and the respective brackets when said connectingmeans are tensioned.

In accordance with one presently preferred embodiment, said sectionsform an elongate substantially planar strip having opposing paralleledges and made from elastomeric material. In this embodiment, the stripis provided with notches at one of said parallel edges which may eitherbe V-shaped or rectangular. In accordance with another embodiment, saidsections are aligned along a substantially straight line and saidconnecting means comprises elastic links connected between opposingportions of adjacent sections. The position or inclination of the linkis selected to generate non-symmetrical forces to the respective bracketrelative to the arch wire when the link is tensioned.

To provide lingual or labial torqueing, at least three sections areprovided and arranged along a straight line generally parallel with thearch wire when said sections are mounted on corresponding brackets. Saidconnecting means provided between each two successive adjacent sectionsexhibits different resistance to twisting. ln

this manner, rotation of a section about said straight line producesnon-symmetrical torqueing action on opposing sides of the respectivesection about the arch wire.

Any conventional bracket engaging means may be utilized. Directedapertures, as described in application Ser. No. 310,572, areparticularly suitable wherein said apertures are directed to correspondto the desired positions in angular orientations of the correspondingteeth on which said sections are mounted.

BRIEF DESCRIPTION OF THE DRAWINGS With the above and additional objectsand advantages in view, as will hereinafter appear, this inventioncomprises the devices, combinations and arrangements of partshereinafter described by way of example and illustrated in theaccompanying drawings ofa preferred embodiment in which:

FIG. 1 is a front elevational view of an orthodontic elastic band inaccordance with the present invention, showing two spaced bracketengaging means each in the form of two spaced apertures, and furthershowing a series of discontinuities in the form of V-shaped andrectangular notches along the upper edge of the strip. Such aconstruction results in non-symmetrical forces in the upper and lowerportions of the strip when the latter is tensioned;

FIG. 2 is similar to FIG. 1, showing the strip with a rectangular notchand showing a tilt limiting elastic portion which bridges the open endof the rectangular notch to prevent excessive separation or tilting ofteeth;

FIG. 3 is a cross section of the band shown in FIG. 2, taken along line33;

FIG. 4 is a front elevational view of an orthodontic device inaccordance with the present invention suitable for mounting on twoadjacent teeth, the device including two circular bracket engagingsections connected by a link;

FIG. 5 is a front elevational view of an elastic band of the type shownin FIG. I mounted on brackets on adjacent teeth which cooperate with anarch wire passing through the channels of the brackets, and showing oneof the sections rotated 180 to tension a transverse connecting link tothereby enhance the torqueing action which counteracts the tiltingforces which would normally be applied to the tooth. The elastic bandmay assume the configuration shown either as a result of tensioning theband or may be pre-formed in the shape shown;

FIG. 6 is a front elevational view of a further embodiment of anorthodontic elastic band in accordance with the present invention,showing a plurality of spaced sections each adapted to engage a bracketon a tooth and connected to each other by diagonal connecting links, asshown on the left side of the FIGURE, the two central sections beingconnected to each other by a transverse connecting link similar to thatshown in FIG. 2, and the right-hand side of the FIGURE showing howsimilar rotating action can be achieved by utilizing transverse links inplace of diagonal links;

FIG. 7 illustrates a practical construction of the clastic band shown inFIG. 6, showing the'band as constructed in solid outline and, in dashedoutline, the

shape it assumes when the respective sections are shifted into positionsfor mounting on the brackets; and

FIG. 8 is a front elevational view ofa still further em-' bodiment ofthe present invention, showing a plurality of spaced sections,successively adjacent sections being connected by different numbers ordifferently dimensioned connecting links, connecting links between eachI DESCRIPTION OF THE PREFERRED I EMBODIMENTS Referring now to theFIGURES, wherein identical or similar parts have been designated by thesame reference numerals throughout, and first referring toFIG. 1, anelastic band in accordance with the present invention is generallydesignated by the reference numeral 1 In accordance with one presentlypreferred embodiment of the invention, the elastic band is generally inthe form of a substantially flat strip of elastic material 1 12, such asrubber or other elastomeric material, and provided with spaced bracketengaging means 14. The bracket engaging means shown in FIG. 1 are in theform of pairs of apertures 14a and 141) which are together adapted toreceive the wings of a single edgewise-type bracket, with the portion ofthe strip between each two apertures being receivable within the channelof a bracket. The general procedure for using such strips and a moredetailed discussion of the types of apertures which can be utilized andthe manner of utilizing the same is set forth in the application Ser.No. 310,572.

An important feature of the present invention is the provision ofdiscontinuities 16 along one of the parallel edges 12a, 12b of the strip12 and between adjacent bracket engaging means 14 to providenon-symmetrical forces applied to the brackets relative to an anchorpoint, such as an arch wire, to generate torqueing forces. Thenon-symmetrical forces referred to herein may also be described asrotational forces applied to the brackets (i.e., to the tooth) so as tocause tilting of a tooth about a fulcrum point.

In FIG. 1, the discontinuity 16 is in the form of a V- shaped notch 18shown to extend to a point approximately midway between the two opposingedges 12a, 12b of the strip. However, as shown by the dashed outlines18a and 18b, the notch can be larger or smaller. The size of the notchdetermines the dimensions of the resulting connecting link 20 which nowconnects the bracket engaging sections. Clearly, tensioning of the link20 generates restoring forces 20a. Accordingly, the dimensions, theposition and orientation of the link 20 are all factors which determinethe directions and magnitudes of the forces 2011. By changing the sizeor shape of the notch 16, the effective position and magnitude of therestoring forces 20a can be changed relative to an imaginarylongitudinal center line which extends through the strip when the latteris stretched. The greater the discontinuity, as successively depicted bythe outline 18a, 18 and 18b, the lower will the forces 20a act, asviewed, in FIG. 1, or the further will the effective forces move fromthe general area of the center line of the strip 12 towards the loweredge 12b thereof.

While the notch 16 has been described thus far as being V-shaped, thenotch may also be rectangular as depicted by the dashed outline 180. Theoperation of the band is similar irrespective of the specificconfiguration of the notch. However, the provision of a rectangularnotch results in a more well defined transverse connecting link betweenopposing portions of the two adjacent bracket engaging sections. Such alink extends in a direction substantially parallel to the longitudinalcenter line of the strip.

When the band is provided with a rectangular notch 18c and is stretchedto separate the bracket engaging means 14, the linking portion 20 isstretched as described above. The formation of a rectangular notch 18bassures that the restoring forces act along the lower edge 12b of thestrip, as viewed in FIG. 1. Thus, the generation of discontinuitiesbetween adjacent bracket engaging portions or sections permits preciselocation of restoring forces which are generated when the elastic stripis tensioned. As will be evident, the length of the rectangular notch 26is not critical and the notch may be as deep or as narrow as desired. Aswith V- shaped notches, the larger the rectangular notch at one edge,the more will the forces be concentrated along the other longitudinaledge of the strip. As to be described hereafter, the restoring forcesincrease the torqueing forces which are exerted upon a tooth relative tothe bracket and arch wire to promote or prevent excessive tilting oruprighting of the tooth.

In FIG. 2, a band 22 is shown which is similar to the band 10. However,the band 22 is in the form of a strip 24 which includes elongate singleapertures 26 each for engaging a single bracket, each single aperturereplacing the twin or pairs of spaced apertures 14a and 14b shown inFIG. 1.

The band 22 includes a rectangular notch 28 between the spaced apertures26, the upper end of the notch being closed by a strand 30. Therectangular notch 28 also forms, as in FIG. 1, a transverse connectinglink 32. The strand 30 is in the form ofa tilt limiting portion whichextends between opposing portions of the two adjacent bracket engagingsections. It is pointed out that while the transverse link 32 isdisposed at a level below the apertures 26, the tilt limiting strand 30is disposed above the bracket engaging apertures. Tensioning orstretching the link 32 generates restoring forces 320 as shown by thearrows while tensioning or stretching the tilt limiting strand 30generates restoring forces 34. The strand 30 may be shorter, equal orlonger than the link 32, for reasons which will become apparenthereafter. It should be clear that the restoring forces 32a and 34result in torqueing of the brackets with respect to an arch wire tocause corresponding torqueing, tilting or uprighting of the teeth onwhich the brackets are mounted. This torqueing effect is achieved byspacing the link 32 and strand 30 sufficiently close to the edges of thestrip 24 to provide a moment arm about the respective bracket aboutwhich the restoring forces can act. As the link 32, for example, becomeswider or the dimensions of the rectangular notch 28 are reduced, therestoring forces 32a shift towards the longitudinal center of the strip24 and torqueing action is soon lost when the restoring forces actdirectly through the brackets. In this condition, the band behavessubstantially similarly to the symmetrical-type bands which aredescribed in the parent application.

The link 32 and the tilt limiting strand 30 are selected to exhibitdifferent elastic characteristics to cause the tilt limiting portion toprevent excessive tilting of a respective tooth only when the transverselink 32 has caused the tooth to tilt a predetermined value withcorresponding excessive tensioning of the tilt limiting strand 30. Asshown in FIG. 2, the cross sectional area of the tilt limiting strand 30is smaller than that of the transverse link 32. Further, the length ofthe tilt limiting strand 30 may be advantageously selected to be longerthan that of the transverse link 32, as suggested above. With such anarrangement, the apertures 26 may be slipped onto two adjacent bracketswith the links 30 and 32 in stretched or tensioned condition. Somounting the band 22 causes corresponding teeth to move towards oneanother primarily due to the forces 32a. However, if the teeth tiltexcessively with respect to one another to result in excessivetensioning of the tilt limiting strand 30 beyond a predetermined value,the latter generates a counteracting or restoring force 34 which opposesfurther tilting. In effect, the restoring forces 34 are selected toprevent excessive movement of the teeth beyond a desired condition dueto the ac tion of the forces 32a.

With respect to the embodiments shown in FIGS. 13, the non-symmetricalor rotational forces which are generated have been described thus far asbeing a function of the extent or configuration of the notches 16.However, it should be clear that any means provided between adjacentbracket engaging sections to generate non-symmetrical forces can equallybe utilized to achieve the objects of the present invention. Thus, it ispossible, for example, to change the thickness of the strip in theregion of one or the other edge thereof to thereby enhance the forces atsaid edge when the strip is stretched.

While the bracket engaging sections of the present invention have thusfar been described as comprising an elongate planar strip, this issimilarly not a critical requirement. In fact, the broader aspects ofthe present invention merely require spaced bracket engaging sectionswhich are connected by links of the type above suggested which result innon-symmetrical forces when tensioned. Referring to FIG. 4, anembodiment 36 is shown which includes two circular bracket engagingsections 38 and 40. The section 38 is provided with bracket engagingapertures 38a and 38b suitable for engaging the wings of a singleedgewise-type bracket. On the other hand, the section 40 is providedwith two pairs of smaller bracket engaging apertures 40a and 40b whichare adapted to be mounted on a double edgewrse-type bracket. Thesections 38 and 40 are connected by means of a link 42 which would, whentensioned, generate a non-symmetrical force upon the respectivebrackets. A further link 44 is shown in dashed outline to illustratethat the length or position of the link is not critical and manyarrangements of the present invention are possible for achieving theobjects thereof. While the embodiment shown in FIG. 4 is adapted for useon two adjacent teeth, a similar construction can be used with a seriesof bracket engaging sections.

An orthodontic system is shown in FIG. wherein a series of bracketengaging sections 50 similar to those shown in FIG. I are mountable onedgewise brackets (not shown) which engage an arch wire 48. The leftmostand center sections 50 in FIG. 5 are to be mounted on anchor teeth. Onthe other hand, the right section 52 is mounted on a tooth which is tobe moved or drawn towards the other two brackets or anchor teeth. Anexample of the way in which the present invention can be utilized isshown where the section 52 is rotated approximately 180 to therebysubstantially stretch the transverse connecting link 56. The link 56,which includes portions 56a and 56b, generates a transverse force whentensioned along the direction of the arch,.wire 58 which tends to drawthe tooth to be moved towards the left. However, because the transverselink 56 acts below the aperture 26 and below the arch wire 48, torqueingforces 520 are simultaneously generated which tend to pivot or rotatethe bracket and tooth to be moved in a clockwise direction. Since thetooth to be moved, in this example, has the roots thereof anchored inthe gum and bone structure, the transverse forces which urge the toothtowards the left would normally simultaneously cause the tooth to pivotin a counter-clockwise direction about its roots. Clearly, the forces52a tend to counteract this normal tendency and promote movement of thetooth towards the left with minimal tilting of the tooth. If, on theother hand, the tooth were initially excessively tilted towards theright,

I and a counter-clockwise torqueing force were desired,

a transverse link could be provided, for example, extending betweenopposing portions of the adjacent sections 50 and 52 above the centerline. Alternately, the transverse link 56 could extend directly from thelower region of the central section 50 to an opposing portion of theright-hand section 52 above the center line, similar to the diagonal oroblique links to be described in connection with FIGS. 6 and 7.

Still referring to FIG. 5, the elastic band 58 shown can assume theconfiguration shown by turning the section 52 as suggested above andresulting in tensioning of the link 56. Alternately, a band may befabricated to include the links 56, 56a and 56b which at least partiallyextend around the periphery of the substantially planar section 52 inthe plane thereof. In this manner, tensioning of the links appliestorqueing action about the respective bracket around which the linkextends.

In FIG. 6, a further embodiment of the present invention is shown whichis generally indicated by the reference numeral 58. The elastic band 58can best be described as comprising a plurality of sections 60 which arespaced from each other and are each provided with bracket engaging meansas described above. As with the sections or portions shown in theprevious Figures, the sections 60 are arranged or aligned, prior to tensioning of the band, along a substantially straight line. In theembodiment of FIG. 6, the sections are aligned with the straight linesubstantially parallel to the arch wire 48 when the sections 60 areoriented in positions prior to mounting on the brackets. Here, theconnecting means which connect the sections 60 to each other may be inthe form of diagonal linking portions or links 62, as shown on the leftof the Figure which extend between opposing portions of each twoadjacent sections and extend in oblique directions relative to thestraight nected by transverse links 64 as shown. Each link ex-' tendsbetween opposing portions of each two adjacent sections. In thepresently preferred embodiment, the oblique links extend between extremeopposing portions proximate the upper and lower edges of the respectivesections 60. One end. section 60 is connected to a buccal end tube andarch wire by means of a loop connected to the end oblique link 66 whilethe other end section is similarly connected by means of a loop 74connected to an oblique link 72. When the band 58 is stretched andmounted on the brackets of corresponding teeth, the teeth experiencetorques as suggested by the directions of the arrows shown in FIG. 6.More specifically, the teeth to the right of the median line of the archwill experience clockwise torques while the teeth on the other side ofthe arch will experience counter-clockwise torques.

While the elastic bands of the type suggested in the Figures may bemanufactured in continuous strips, such bands can also be formed fromthe bands disclosed in the parent application. When utilized incombination with or derived'from symmetrical bands, dis.

continuities or notches can be added by suitably punching out the samein any conventional manner along one or the other of both edges of theband.

It should be pointed out that the dimensions shown inthe Figures are notnecessarily to scale and some exaggerations have been made to moreclearly show the important structural features of the band. It should bepointed out, however, that the bands under discussion are generally verysmall and manufacturing problems may arise in their construction. Forexample, the left side of the band shown in FIG. 6 may not be convenientfor manufacturing because of the small dimensions of the links as wellas the small spaces between adjacent sections in which the oblique linksare to be formed. In FIG. 7, a slightly modified band is shown which maybe more easily manufactured but which can nevertheless be converted, forall practical purposes, into a'band as shown at the left of FIG. 6. Morespecifically, the sections 60 are arranged, prior to tensioning of theband or the links, along a straight line which forms an angle with thearch wire when the sections are oriented, as shown, in positions priorto mounting on the brackets. Now, the links are merely short sectionswhich connect proximate corners of adjacent sections. To obtain theoblique links 62 shown in FIG. 6, each of the sections is shifted ordisplaced downwardly as suggested by the dashed outlines. Such downwardmovement of the sections tensions the links 62 and disposes the links inthe desired positions indicated in FIG. 6. Thus, the band as shown inFIG. 7 is one possible structural approach to obtain the band shown inFIG. 6.

7 Since the orthodontic band of the present invention is primarilyintended to regulate the tilting and uprighting forces exerted on teethwhile the same are being transversely moved distally or mesially, tiltlimiting means such as the tilt limiting strand 30 maybe incorporated inany of the described embodiments to prevent excessive tilting oruprighting. An important feature of the present invention is that theconnecting links which connect two bracket engaging sections extendbetween points on adjacent sections which would not result insymmetrical forces being applied on-these sections when the link istensioned.

, A still further embodiment of the present invention is shown in FIG.8, wherein an elastic band 76 is shown suitable for lingually orlabially torqueing a tooth. Such a band is described in the parentapplication. However, the twisting of the portion of the band 76 whichresults in lingual or labial torqueing also results in counter forcesapplied to adjacent teeth. Since these counter forces can be substantialand are generally applied to teeth which are not rigidly anchoredthemselves, undesired movements of adjacent teeth may result. The band76 of the present invention eliminates this problem by redistributingthe counter forces along the arch and shifting the major components ofthese forces distally towards the bigger and better anchoring teeth. Toachieve this, the band 76 comprises a plurality of sections 78a78f. Theadvantages of the present band can be realized when at least threeanchoring sections are provided. The sections are respectively connectedor joined by links 80, 82, 84, 86 and 88, not necessarily in the ordershown. These links may be symmetrically or asymmetrically connected tothe bracket engaging sections. However, each of the links exhibitsdifferent resistance characteristics to twisting. The differentresistant characteristics may be achieved in numerous ways. For example,the cross sectional dimensions of the links or lengths, may bedifferent. Alternately, dif ferent numbers of links may be provided ortheir positions with respect to the arch wire can also be different. Anyof these factors will result in different resistance to twisting of asection and of the general plane of the band 76. For example, the links80 and 82 are both centrally located except that the link 82 issubstantially thinner than the link 80 and therefore will exhibit asmaller resistance to twisting. Similarly, the links 84 and 86 are eachin the form of two spaced links along the edges of the band 76. However,the links 86 are thicker and therefore will exhibit higher resistance totwisting. The links 88 are in the form of three links, two peripherallinks and one central link. Clearly, numerous combinations andpossibilities may be found which will provide the desired twistingresistance characteristic for a particular application.

In the use of the band 76 shown in FIG. 8, resistance characteristics ofthe various links are advantageously selected so that a single twist ofa given bracket engaging section is all that is required to provide therequisite lingual or labial torque on a tooth. Simultaneously, a singleturn of the other sections of the band is all that is necessary tocompensate for the counteracting forces, the forces being transmitted toadjacent teeth with subsequent sections having counter twists to furthercompensate for these counter forces, the counter forces being therebyshifted distally towards the larger and better anchoring teeth. In thismanner, the teeth in the region of the lingually or labially torquedtooth, which may not be capable of withstanding the high counteractingtorques or moments without physically shifting in position, aresubstantially relieved of these forces.

As described above, the Figures above described are merely illustrative.The actual proportions or dimensions of the bands may be modified tosuit a particular application. For example, while the bracket engagingsections have been generally designated as being flat and planar, thesesections may be strand-like wherein each of the bracket engagingapertures is defined by strands of elastic material which define thebracket engaging sections. Further, it is not necessary that thesections be planar or flat and, in fact, the elastic portions may assumeany cross sectional configuration, as suggested above, to enhance orreduce the amount of restoring forces which are generated when variousportions of the band are tensioned.

Numerous alterations of the structure herein disclosed will suggestthemselves to those skilled in the art. However, it is to be understoodthat the present disclosure relates to a preferred embodiment of theinvention which is for purposes of illustration only and is not to beconstrued as a limitation of the invention.

What is claimed is:

1. An orthodontic, elastic band for use with orthodontic arch bracketsmounted on teeth misaligned from their desired positions, the bandcomprising a plurality of spaced sections each provided with bracketengaging means for substantially non-rotatably engaging a respectivebracket; and elastic connectingmeans coupling adjacent sectionstogether, said elastic connecting means being located with respect tosaid adjacent sections and dimensioned for generating and applyinggenerally rotational forces to said adjacent sections and theirrespective brackets when said connecting means are elasticallytensioned.

2. An orthodontic band as defined in claim 1, wherein said bracketengaging means comprise directed apertures in said sections directed tocorrespond to the desired positions and angular orientations of thecorresponding teeth on which said sections are mounted.

3. An orthodontic band as defined in claim 1, wherein said sectionscomprise an elongate substantially planar strip having opposing paralleledges and made from an elastomeric material.

4. An orthodontic band as defined in claim 3, wherein said strip isprovided with notches at one of said parallel edges between adjacentbracket engaging means to form said connecting means.

5. An orthodontic band as defined in claim 4, wherein said notches aregenerally V-shaped.

6. An orthodontic band as defined in claim 4, wherein said notches aregenerally rectangular.

7. An orthodontic band as defined in claim I, wherein said sections arealigned along a substantially straight line, and wherein said connectingmeans comprises an elastic link connected between opposing portions oftwo adjacent sections.

8. An orthodontic band as defined in claim 7, for use with an arch wire,and wherein said sections are arranged, prior to tensioning of saidlink, with said substantially straight line substantially parallel to anarch wire when said sections are oriented in positions prior to mountingon the brackets.

9. An orthodontic band as defined in claim 7, wherein said link extendsbetween opposing portions of two adjacent sections and extends in adirection substantially parallel to said substantially straight line.

10. An orthodontic band as defined in claim 7, wherein said link extendsbetween opposing portions of two adjacent sections and extends in anoblique direction relative to said substantially straight line.

11. An orthodontic band as defined in claim 7, for use with an archwire, and wherein said sections are arranged, prior to tensioning ofsaid link, with said sub-' stantially straight line forming an anglewith the arch wire when said sections are oriented in positions prior tomounting on the brackets.

12. An orthodontic band as defined in claim 11, wherein said sectionsare generally rectangular in shape and adjacent sections are spaced fromeach other along said substantially straight line to disposecorresponding opposing corners of said sections into proximity to eachother, said link extending between said corresponding opposing corners,whereby positioning said sections in orientations for mounting on thebrackets along a substantially straight line substantially parallel tothe arch wire tensions said links and the latter assume obliqueorientations relative to the arch wire.

13. An orthodontic band as defined in claim 1, further comprisingelastic tilt limiting means extending between said two adjacent sectionsfor preventing excessive tilting of a respective tooth only when saidconlimiting means.

14. An' orthodontic band as defined in claim 1,

wherein, said sections are substantially planar and wherein said elasticconnecting means is in the form of an elongate elastic link extendingbetween two sections, said link at least partially extending around theperiphery of at least one of said sections in the plane of the latter,whereby tensioning of said link applies a torqueing action about therespective bracket around which said link extends.

15. An orthodontic band as defined in claim 1, wherein said sections areformed of strand-like material.

16. An orthodontic band as defined in claim 1, wherein said bracketengaging means comprises two spaced openings arranged along a linedirected to cor-' respond to the desired positions and angularorientations of the corresponding teeth on which said sections aremounted.

17. An orthodontic band as defined in claim 16, wherein said openingsare circular.

18. An orthodontic elastic band for use with orthodontic arch bracketsmountedon teeth'misaligned from their desired positions, the bandcomprising a plurality of spaced sections each provided with bracketengaging means for substantiallynon-rotatably engaging a respectivebracket; and elastic connecting means coupling adjacent sectionstogether, and having a resis+ tance to twisting, said elastic connectingmeans being located with respect to said adjacent sections anddimensioned for generating and applying torqueing forces to saidadjacent sections and their respective brackets when one of saidsections is rotated relative to the other sections to twist said elasticconnecting means.

'19. An orthodontic band as defined in claim 18, comprising at leastthree of said sections, and wherein said connecting means betweensuccessive pairs of adjacent sections include different numbers oflinks. I

20. An orthodontic band as defined in claim 18, comprising at leastthree of said sections, and wherein said connecting means betweensuccessive pairs of adjacent sections include links having differentcross sections.

21. An orthodontic band as defined in claim 18, comprising at leastthree of said sections, and wherein said connecting means betweensuccessive pairs of adjacent sections extend between different opposingcorresponding sections. Q r r 22. An orthodontic band as defined inclaim l8com- 1 prising at least three sections with saidelasticconnecting means interposed therebetween, whereby rotation of asection produces torqueing forces acting on opposing sides of therespective section.

23. An orthodontic band as defined in claim 18 wherein said connectingmeans between sections of at least one pair of adjacent sectionscomprises a link substantially centrally located relative to saidsections and extending therebetween.

24. An orthodontic band as defined in claim 18 wherein said connectingmeans comprises a pair of spaced links extending between a pair ofadjacent sections.

25. An orthodontic device according to claim 26 wherein said pair ofspaced links extend substantially along the edges of the band betweenadjacent sections.

26. An orthodontic device according to claim 1 wherein said bracketengaging means comprises a plurality of spaced openings,

portions of g

1. An orthodontic elastic band for use with orthodontic arch bracketsmounted on teeth misaligned from their desired positions, the bandcomprising a plurality of spaced sections each provided with bracketengaging means for substantially nonrotatably engaging a respectivebracket; and elastic connecting means coupling adjacent sectionstogether, said elastic connecting means being located with respect tosaid adjacent sections and dimensioned for generating and applyinggenerally rotational forces to said adjacent sections and theirrespective brackets when said connecting means are elasticallytensioned.
 2. An orthodontic band as defined in claim 1, wherein saidbracket engaging means comprise directed apertures in said sectionsdirected to correspond to the desired positions and angular orientationsof the corresponding teeth on which said sections are mounted.
 3. Anorthodontic band as defined in claim 1, wherein said sections comprisean elongate substantially planar strip having opposing parallel edgesand made from an elastomeric material.
 4. An orthodontic band as definedin claim 3, wherein said strip is provided with notches at one of saidparallel edges between adjacent bracket engaging means to form saidconnecting means.
 5. An orthodontic band as defined in claim 4, whereinsaid notches are generally V-shaped.
 6. An orthodontic band as definedin claim 4, wherein said notches are generally rectangular.
 7. Anorthodontic band as defined in claim 1, wherein said sections arealigned along a substantially straight line, and wherein said connectingmeans comprises an elastic link connected between opposing portions oftwo adjacent sections.
 8. An orthodontic band as defined in claim 7, foruse with an arch wire, and wherein said sections are arranged, prior totensioning of said link, with said substantially straight linesubstantially parallel to an arch wire when said sEctions are orientedin positions prior to mounting on the brackets.
 9. An orthodontic bandas defined in claim 7, wherein said link extends between opposingportions of two adjacent sections and extends in a directionsubstantially parallel to said substantially straight line.
 10. Anorthodontic band as defined in claim 7, wherein said link extendsbetween opposing portions of two adjacent sections and extends in anoblique direction relative to said substantially straight line.
 11. Anorthodontic band as defined in claim 7, for use with an arch wire, andwherein said sections are arranged, prior to tensioning of said link,with said substantially straight line forming an angle with the archwire when said sections are oriented in positions prior to mounting onthe brackets.
 12. An orthodontic band as defined in claim 11, whereinsaid sections are generally rectangular in shape and adjacent sectionsare spaced from each other along said substantially straight line todispose corresponding opposing corners of said sections into proximityto each other, said link extending between said corresponding opposingcorners, whereby positioning said sections in orientations for mountingon the brackets along a substantially straight line substantiallyparallel to the arch wire tensions said links and the latter assumeoblique orientations relative to the arch wire.
 13. An orthodontic bandas defined in claim 1, further comprising elastic tilt limiting meansextending between said two adjacent sections for preventing excessivetilting of a respective tooth only when said connecting means has causedthe tooth to tilt to a predetermined value with corresponding tensioningof said tilt limiting means.
 14. An orthodontic band as defined in claim1, wherein said sections are substantially planar and wherein saidelastic connecting means is in the form of an elongate elastic linkextending between two sections, said link at least partially extendingaround the periphery of at least one of said sections in the plane ofthe latter, whereby tensioning of said link applies a torqueing actionabout the respective bracket around which said link extends.
 15. Anorthodontic band as defined in claim 1, wherein said sections are formedof strand-like material.
 16. An orthodontic band as defined in claim 1,wherein said bracket engaging means comprises two spaced openingsarranged along a line directed to correspond to the desired positionsand angular orientations of the corresponding teeth on which saidsections are mounted.
 17. An orthodontic band as defined in claim 16,wherein said openings are circular.
 18. An orthodontic elastic band foruse with orthodontic arch brackets mounted on teeth misaligned fromtheir desired positions, the band comprising a plurality of spacedsections each provided with bracket engaging means for substantiallynon-rotatably engaging a respective bracket; and elastic connectingmeans coupling adjacent sections together, and having a resistance totwisting, said elastic connecting means being located with respect tosaid adjacent sections and dimensioned for generating and applyingtorqueing forces to said adjacent sections and their respective bracketswhen one of said sections is rotated relative to the other sections totwist said elastic connecting means.
 19. An orthodontic band as definedin claim 18, comprising at least three of said sections, and whereinsaid connecting means between successive pairs of adjacent sectionsinclude different numbers of links.
 20. An orthodontic band as definedin claim 18, comprising at least three of said sections, and whereinsaid connecting means between successive pairs of adjacent sectionsinclude links having different cross sections.
 21. An orthodontic bandas defined in claim 18, comprising at least three of said sections, andwherein said connecting means between successive pairs of adjacentsections extend between different opposing portions of correspondingsections.
 22. An orthodontic band as defined in claim 18 comprising atleast three sections with said elastic connecting means interposedtherebetween, whereby rotation of a section produces torqueing forcesacting on opposing sides of the respective section.
 23. An orthodonticband as defined in claim 18 wherein said connecting means betweensections of at least one pair of adjacent sections comprises a linksubstantially centrally located relative to said sections and extendingtherebetween.
 24. An orthodontic band as defined in claim 18 whereinsaid connecting means comprises a pair of spaced links extending betweena pair of adjacent sections.
 25. An orthodontic device according toclaim 26 wherein said pair of spaced links extend substantially alongthe edges of the band between adjacent sections.
 26. An orthodonticdevice according to claim 1 wherein said bracket engaging meanscomprises a plurality of spaced openings.